Antimicrobial Susceptibility of Ertapenem in Neisseria gonorrhoeae Isolates Collected Within the China Gonococcal Resistance Surveillance Programme (China-GRSP) 2018

Figures & data

Table 1 The Proportions of the Isolates with Different MICs of Ertapenem by Provinces

Province	Isolates Detected	MIC (mg/L)			MIC ≥ 0.25 mg/L
		Range	MIC50	MIC90	n (%)	P-value
Beijing	40	0.03–0.25	0.06	0.125	1 (2.5%)	1.0000
Guangdong	59	0.015–0.25	0.06	0.125	4 (6.8%)	0.1252
Guangxi	53	0.015–0.25	0.06	0.125	2 (3.8%)	0.6655
Liaoning	38	0.015–0.125	0.06	0.06	0	0.6109
Sichuan	67	0.015–0.25	0.03	0.125	2 (3.0%)	1.0000
Shaanxi	52	0.015–0.5	0.06	0.06	2 (3.9%)	0.6617
Tianjin	48	0.015–0.125	0.03	0.06	0	0.6230
Yunnan	58	≤0.008–0.25	0.03	0.06	1 (1.8%)	1.0000
Total	415	≤0.008–0.5	0.06	0.125	12 (2.9%)

Notes: P-value was the chi-square of isolates with MIC ≥ 0.25 mg/L in different provinces to total.

Figure 1 The percentage of N. gonorrhoeae isolates with different MICs (mg/L) for ertapenem. The MIC₅₀ (yellow-dotted line), MIC₉₀ (red-dotted line) and number of isolates per province are shown.

Abbreviations: BJ, Beijing; GD, Guangdong; GX, Guangxi; LN, Liaoning; SC, Sichuan; SX, Shaanxi; TJ, Tianjin; YN, Yunnan; n, number.

Figure 2 Correlation between MICs of ertapenem and ceftriaxone or azithromycin. Each symbol represents one or multiple isolates, which is also shown with specific numbers and colors. The regression line was calculated using log₂-transformed MIC data. For the MICs ≤ or ≥ a specific value, log₂-transformed this specific value was used for calculating linear regression. (A) Correlation between MICs of ertapenem and ceftriaxone, r = 0.487, P <0.001. (B) Correlation between MICs of ertapenem and azithromycin, r = −0.12, P = 0.007.

Table 2 Ertapenem MICs Distributions for Decreased Susceptibility to Ceftriaxone (DSC) or Azithromycin-Resistant (RTA) N. gonorrhoeae Isolates

Ertapenem MIC (mg/L)	DSC			RTA
	Number	Percentage	Cumulative %	Number	Percentage	Cumulative %
≤0.008	0	0	0	1	1.2	1.2
0.015	0	0	0	13	15.3	16.5
0.03	1	4.2	4.2	30	35.3	51.8
0.06	9	37.5	41.7	35	41.2	92.9
0.125	10	41.7	83.3	3	3.5	96.5
0.25	3	12.5	95.8	1	1.2	97.6
0.5	1	4.2	100.0	2	2.4	100.0
Sum	24	100.0		85	100.0